I. Field of Invention
The invention relates in general to a device for randomizing a probabilistic pulse train. More specifically, the device receives as input a probabilistic pulse train and outputs a randomized probabilistic pulse train of identical data value wherein the probability of output pulses occurring are identical, but the output is statistically independent of the input.
II. Background Art
A data value may be transmitted on a line in the form of a probabilistic pulse train, i.e. a pulse train wherein the data value is represented by the probability of the line being active ("on", high, one, also inverted). In the course of computation using probabilistic pulse trains, often it is necessary for the probabilistic pulse trains on separate lines to be statistically independent. Also, sometimes, during the course of computation, results on separate lines to become statistically dependent.
As an example, if the values X, A and B are represented by statistically independent pulse trains to calculate AX and BX, by simply logically AND'ing the appropriate pulse trains. However, the logical AND'ing of statistically dependent pulse trains does not result in a proper multiplication. Because both the logical AND's utilize the same probabilistic pulse train X, the resultant probabilistic pulse trains AX and BX are not statistically independent. Therefore, if they are to be used in situations which require statistical independence, such as producing the product ABX.sup.2, the AX and BX signals cannot be simply AND'ed. Hence, to calculate ABX.sup.2, it is necessary to "re-randomize" AX, BX, or both, by changing one or both of the probabilistic pulse trains AX and BX such that they are statistically independent of one another.
Therefore there is a need for a re-randomization circuit.